Fluid separator



Jan. 20, 1948. ms- 2,434,637

FLUID SEPARATOR Filed Feb. 11, 1943 78 INVENTOR.

a; ATTORNEY Patented Jan. 20, 1948 FLUID SEPARATOR Paul M. Brister,Madison, N. J., assignor to The Babcock & Wilcox Company, Rockleigh, N.J., a corporation of New Jersey Application February 11, 1943, SerialNo. 475,475

This invention relates to separators for fluids of different densities,and, more particularly to a centrifugal fluid separator.

A preferred embodiment of the invention involves a substantiallycircular whirl chamber into which a high velocity stream of steam andwater mixture is tangentially discharged so as to set up a whirlingmotion within the chamber. As a consequence of the centrifugal actionwithin the whirl chamber steam is separated from the water and theseparated steam exits through a central upper outlet while the separatedwater is discharged through a lower outlet.

An object of the invention is to provide for the control of the outflowof separated steam from the steam outlet in such a manner as to collectentrained moisture particles on the surface of a perforated memberarranged across the steam flow path and drain the collected particles toa lower central whirl chamber position at which a relatively lowpressure condition exists.

It is also an object of the invention to so arrange the extent andproportions of perforated members to uniformly distribute the steam flowand maintain the separator outlet velocity below a critical value sothat moisture particles will not be entrained in the steam.

The invention contemplates the use of the illustrative separator in ahigh pressure steam generator, to improve circulation and to enable thegenerator to operate under high and/or unstable drum water levelconditions and still supply steam of high quality.

The invention will be described with reference to the accompanyingdrawings in which a preferred embodiment of the invention is shown, andother objects of the invention will appear as the description proceeds.

In the drawing:

Fig. 1 is a diagrammatic view in the nature of a vertical sectionshowing a steam generator in connection with which the invention isemployed;

Fig. 2 is a detailed view in the nature of a vertical transverse sectionthrough the steam and water drum of the Fig. 1 installation;

4 Claims. (Cl. 183-83) Fig. 3 is a vertical section of the illustrativeseparator, and

Fig. 4 is a horizontal, or plan, section. of the separator on the line44 of Fig. 3.

The illustrative separator includes a substantially circular whirlchamber I0 formed by a shell or casing l l and having an inlet I2through which a mixture of steam and water is discharged substantiallytangentially and at high velocity into the whirl chamber.

The introduction of a high velocity mixture of steam and water sets up avertical action of the mixture with the water thrown outwardly againstthe cylindrical whirl chamber wall by the centrifugal effect while thesteam which is of lower density is displaced toward the central portion.This action also induces a zone of lower pressure at the axial center ofthe whirl chamber.

Steam is separated from the water within the Whirl chamber, the steampassing upwardly through a central steam circular outlet M defined by acylindrical member Ida and then through a scrubber or multiple steam andwater separator l6 spaced from the top of the whirl chamber to providethe auxiliary lateral steam outlet H. The separated water is dischargeddownwardly through circumferentially arranged outlets l8 betweensuccessive helical vanes such as those shown at 20 and 22.

The member I la is a shield between the upper part of the inlet l2 andthe perforated hollow cone baffle 24.

To minimize the discharge with the separated steam of entrained dropletsof water, an inverted perforated metallic cone 24 is disposed with itsapex within the whirl chamber and its base 26 is secured to the topflange 28 of the whirl chamber casing as clearly indicated in Fig. 3 ofthe drawing. The sum of the flow areas of the perforations in the cone24 is at least as great as the free flow area of the circular steamoutlet l4. and the perforated cone accomplishes the following results:

(a) It equalizes the outlet steam velocity at various transversepositions across the outlet H! by introducing the flow restrictiveeffect of the plurality of spaced orifices, while eliminating the majorportion of the angular movement of the steam flow.

(b) It acts as a barrier to collect by cohesion any entrained dropletsof water tending to pass upwardly with the steam.

(c) It drains the collected water toward a position centrally of thevortex within the chamber. ((1) It returns the collected water to thewater in the whirl chamber at a zone of decreased pressure so as tominimize reentrainment.

(e) By providing a uniform steam velocity condition approaching themultiple plate separator IE, it equalizes the loading of the separatorresulting in an improved separating effect.

(1) It directly affects the functioning of the separator [6 by breakingup any slugs of water which might otherwise attempt to pass through thatseparator. under some conditions. In this way the cone 2 5 permits themultiple plate separator to function in the most efiective manner.

Preferably the vanes 20 and 22 between 5110-. cessive outlets forseparated water are secured in an annular passage at the bottom of thewhirl chamber casing M. This annular passage is defined by the uprightwall of a pan 42 and: the bottom portion of the wall of the whirlchamber as indicated in Figs. 2 and 3.

A number of separators may be secured within the steam and water drum50, and, for this pur- V pose, the steam and water inlet structure F2for each separator is provided with a heavy flange 52 for secureinent toa similarly formed flange 54 secured to the upright wall 5.6 of an inletcompartment 58.

Steam and water mixtures are discharged into the inlet compartment 58 bythe steam generating tubes 66i33, and separated water from the whirlchambers Iii passes downwardly from the water space 4510f the drum 5%through the downcomers 51 and other external downcomers which are notshown in the drawing. Steam from the separator l passes from the drumthrough a steam. offtake M and is conducted thence to a superheaterwhich is indicated in Fig. 1 as consisting of two sections 7.8 and 8B.

The main boiler furnace 82 is fired by burners 8.336 and the auxiliary,or superheater furnace 530,. is independently fired by the burners92-434, the two furnaces being separated by the superheater and thesteam generating tubes 6.0 and 6| which directly connect the water drumIll!) with the inlet compartment 53 of the drum 5.0L.

Furnace gases from the main furnace 82 pass acrossa bank of tubesdirectly connecting a submerged drum l-EI2 to the inlet compartment 58.Some of these tubes are indicated at 62 and 63 in Fig. 1. Beyond thesetubes the gases next contact the tubes of an economizer Hi4- disposedwithin a gas pass Hi5 leading to a flue.

When the superheater furnace is operating, furnace gases therefrom passacross the tubes of the superheater and then across the upper parts ofthe tubes 61-453 where they join the gases from the main furnace.

What is claimed is:

1. In a fluid separator, a casing providing an upright whirl chamberwith an upper perimetral inlet through which there is a high velocitytangential flow of a mixture of fluids of different densities, thecasing having a top rim structure presenting an upper whirl chamberoutlet for separated fluid of lesser density, the upper outletcommunicating with the central part of the whirl chamber, an auxiliaryseparator including spaced fixed members and disposed above said upperoutlet so as to provide an auxiliary outlet between the top of the whirlchamber. and the auxiliary separator, a lower whirl chamber outlet for aseparated fluid of greater, density, and, an inverted conoidal baffleextending downwardly into the whirl chamber and across the upward pathof all of the lesser density fluidtoward the upper whirl chamber outlet,the baffle extending entirely across said upper whirl chamber outlet ata level below that of the auxiliary outlet and having multiple openingsor perforations over its area, said bafile also having its perforatedside portions converging downwardly from the perimeter of said upperoutlet toward a position centrally of the whirl chamber and being soconstructed that the total flow area of its perforations is at least asgreat as the free flow area of the upper whirl chamber outlet.

2. In a fluid separator, a casing presenting an uprightv whirl chamberwith. an. inlet through which there is a high velocity tangential flowof a mixture of fluids of different densities, the casing having a rimstructure at the top of the whirl chamber forming an upper outlet forseparated fluid of lesser density, the casing also having. abottomstructure forming a lower outlet for a, separated fluid of greaterdensity, an auxiliaryseparator; including spaced fixed elements andspaced above said upper outlet so as to leave an auxiliary topoutletbeneath the auxiliary separator and laterally of said upper outlet, andan inverted conoidal bafileextending downwardly into the whirl chamberand across the path of all fluid flowing toward said auxiliary outletand the upper whirl chamber outlet, said bafile having side portionsconverging downwardly toward a position centrally of thewhirlichamberand being so constructed that the total flow area of. its perforationsis at least as great as the free flow area of the upper whirl chamberoutlet, the conoidal baflle being also secured. to the top of the whirlchamber so that it is disposed; entirely b low the level of theauxiliary'top outlet.

3. In a centrifugal separator for different density fluids one of whichis a liquid, a casing forming an upright circular whirl: chamber and awhirl. chamber inlet through which there is a tangential high velocityflow of a mixture of fluids of difierent densities, an upper whirlchamber outlet. for separated fluid of lesser density, a lower whirlchamber outletfor separated liquid, a perforated bafile having thesurface of an inverted perforated hollow cone extending dOWnwardly intothe whirl chamber from said upper whirl. chamber outlet and. having aperimetricbase securedtjogthe topofthe whirl chamber casing around the,perimeter of the upper whirl chamber outlet, and a curved shieldinterposed relative to the baffle and the upper part of said. inlet,the. sum of. the flow areas of the perforations of the. hollow. cone.being at least as great asv the. free. flow area of the upper whirlchamber outlet and the Whirlchamber and the baflle. being. of suchconstruction, that. they fo m downwardly diverging wallsv for the fluidspace therebetween.

4,. In a. entrifugalseparator for fluids of different. densities, a.casing forming. an upright whirl chamber and a whirlchamber inletthrough which there is a high velocity flow of amixture of fluids ofdifierent densities, the casing having a top rim, structure forming anupper whirl. chamber outlet for separatedifluid of; lesser density, aultip plate. auxiliary separator disposed. above the upp r.v Whirlchamber outlet, the separator and itssuppprt beingspacedfromthe casinand thereby forming an. auxiliary whirl chamber outlet disposed.laterally of. said upper outlet and above the whirl chamber, the casinghaving. a bottom structure. forming a lower whirl chamber outlet for aseparated fluid of greater density, said lower ou let. being; Iimited.to. a. marginal. or. circular zone around the bottom of the whirl cham-5 6 her casing, and a perforated bafile having an in- REFERENCES CITEDverted conoldal surface with its apex presented downwardly within thewhirl chamber vortex, The following references are of record in the thebaffle having its base secured to and termifil Of hi p t nating at thetop of the whirl chamber casing in 5 UNITED STATES PATENTS such a mannerthat all fluid flowing to the auxiliary and upper outlets must passthrough the Number Name Date baflie openings, the sum of the flow areasof the 383,301 Downton May 1383 openings through the baffle being atleast as 2,293,285 Fletcher 1942 great as the free flow area of saidupper whirl 10 F I N P s chamber outlet" Number Country Date M. GreatADI. 20,

